For Vanilla batter:
1/2 cup melted butter, 1/2 cup milk, vanilla flavour 2 tbsp, 1/2 cup maida, 1 tbsp milkmaid, 1/2 tsp baking powder, 1/4 baking soda,
Mix well the batter.

For chocolate batter
1/2 cup melted butter, 1/2 cup water, cocoa powder 2 tbsp, 1/2 cup maida, 1 tbsp milkmaid, 1/2 tsp baking powder, 1/4 baking soda,
Mix well the batter.

Now in a cake vessel, add both vanilla and chocolate batter in a way that should form a marble design after baked.

Now stir the cake batter slowly in zigzag style, so that after forming it should look like marble design.

Now bake the batter for 20 mins.
Finally, Serve the marble cake slices.